Miniature modular relay



Sept. 19, 1961 c. R. RHODES 3,001,048

MINIATURE MODULAR RELAY Filed July 29, 1959 FIG. 3. FIG. 1. as 37 38 I0 [l2 7 36 N s 33 3| 33 ll- 34 2. 1 2 30 I8, ID 3 zeize 0 JL I7 I N FIG. 4.

INVENTOR.

CHESTER R. RHODES BY KM AGENT United States, Patent Q 3,001,048 MINIATURE MODULAR RELAY Chester R. Rhodes, Whittier, Calif., assignor to Electro- Mechanical Specialties 'Co., Inc., Whittier, Calif a corporation of California v I I Filed July 29 1959, Ser. No. 830,350

11 Claims. ,(Cl; 200--'87) My invention relates to electricalrelays and particularly to such having few parts toenable economical manufacture of high performance units of multiple nature. While size and multiplicity per se do'not lend novelty .to a device it will be recognized subsequently herein that Ihave evolved embodiments directed to these ends which have easily recognized advantages over the prior art.

When it was desired to reduce the size of eithera single or a multiple relaystructure in the past it has been usual practice to merely scale down a previous larger embodiment. This practice results in certain of the parts becoming so small that microscopes or magnifying glasses have been required for the manufacture and assembly thereof. Such processing is expensive.

By awide departure from this technique I have been able to make a small relay of very few parts, each' of which is relatively large, so that my device may be easily and inexpensively fabricated. and assembled. Furthermore, certain characteristics of my new structure are such that an improvement in operating performancehas been achieved over the larger devices or even over the scaled down versions thereof of the prior art.

In the embodiments composed of multiples of a single relay unit I have been able to'achieve further simplifications and an improvement in the performance of such de- VlC6S..

Briefly, I form anarmature exclusively of one piece of spring magnetic material. This is provided with an electrical contact, such as a small rivet of silver at the free end thereof and the other end is rigidly fastened to a stationary magnetic assembly. The latter has roughly a U-shape, with the extremity awayfrom the rigid attachment of the armature adjacent to the free end of the armature and near the contact thereon. A coil surround.- ing the stationary magnetic member intermediate the extremities thereof provides actuating magnetomotive force to attract the armature. A permanent magnet having, for instance, the shape of a small cube, is positioned closed. A third contact is located adjacentto the contact on the armature but on the side thereof opposite to the permanent magnet. The third contact makes contact with the armature contact when the coil is energized. Because of the cantilever configuration of the armature Patented Sept. 19, 1961 I am able to form a multicontact relay in compact form. An object of my invention is to provide a small electrical relay of few and relatively large parts.

Another object is to provide a relay of superior characteristics. Another object is to provide a relay structure suited for multiple embodiment. 5

Another object is to form a relay of such materials as to attain novel electrical functioning and/or a simplified mechanical structure.

Another object is to provide electrical relay means that are easy and inexpensive to manufacture.

Other objects will become apparent upon reading the following detailed specification and upon examining the accompanying drawings, in which are set forth by way of illustration and example certain embodiments of my invention.

FIG. 1 shows an elevation of one unit of an embodiment of my invention with the base thereof in section,

FIG. 2 shows a plan view of two units of the same embodiment,

FIG. 3 shows an elevation of a ferrite core embodiment of my invention, and

FIG. 4 shows a plan view of a quadruple ferrite em bodiment.

In FIG. 1 numeral 1 indicates the base of my relay structure. This is preferably of amagnetic material, such as iron or steel, while the portion 2 is a glass or ceramic electrical insulating material. These two kinds of materials are rigidly bonded together in the known manner of the header construction in this art. Embedded in the glass material are pluralheader pins, of which 3 and 4 are shown in FIG. 1. The stationary magnetic path is provided mainly by a bobbin structure. This has an extremity 5, to which armature 6 is rigidly fastened. The armature is formed of a magnetic spring material, of which I have found blue clock spring suitable. This is bent at a right angle at extremity 5 and is clampedbetween that extremity and a backup plate 7 by suitable fastening means'such .as rivets 8. The stationary magnetic .path is further comprised of central core 9, which is shown dotted in FIG. 2. The opposite extremity 10 is also magnetically connected to core 9. Extremity 10 passes near armature 6, as may be seen in FIG. 2. The gap here in a typical embodiment may be of the order of eight thousandths of an inch. FIG. 1' has been shown approximately four times full size for clarity.

Coil 11, in the form of a multilayer solenoid, occupies thesp'ace on core v9 between extremities 5 and 10, and

provides actuating magne'tomotive force when electric magnetic assembly and contacts and, the inherent flexibility of the armature, a small but effective wiping action occurs at the contacts. The desirability of this wiping action is known.

Bystaggeringthe positions of plural such relay units upon a mount'of magneticmaterial I am able to sub- .stantially eliminate malfunctioning of one unit upon the netic member I amable to attach contacts directly thereto; the ferrite being an excellentelectrical insulator while still having the properties of the defined magnetic-ma terial. Thisresults in a simplified mechanical structure;

By widening the stationary magnetic member in an alternate embodiment and by providing plural armatures the usual impedance for 28 V. DC. operation, or for any other nominal voltage direct current operation. Also, shading coil shorted turn .12, shown dotted in FIG. 1, may be employed for alternating current operation. Alternating current operation is particularly easily achieved in my relay, as will be explained below. Because my armature 6 is so light in weight the opcrate time to change from. normally closed to normally open contacts (or vice versa) is very short. It is from 0.5 to-().7 millisecond in representative embodiments. The weight of my armatur'e'is of the order of 70 to mil: ligrams. The operate time of ordinary relays is of the order of 3 to 5 milliseconds and the weight of the ordinary armature, complete with contacting structure, etc., as much as a half ounce (14 grams).

Since the operate time of my relay is short the shading coil 12 may be ofrelatively minor dimensions and proper operationjon-altern'ating current is easily accomplishedi --Coil 11 is insulated from stationary magnetic member's 5, 9 and '10 as usual. n

tact on the armature is completed through the magnetic assembly; i.e., electrical contact. 14, armature 6 and the magnetic assembly are all connected electrically. As an alternate construction armature 6 may be clamped 'between thin slabs of insulating material between extremity 5 and backup plate 7. As shown in FIG. 1, external connection 3 is welded or soldered to extremity ltl and performs the dual function of'external connection to con- -permanent,magnet 18. This is in the shape of a short cylinder in'this embodiment and it may be magnetized with. the orientation of the poles in almost any way. Armature. 6 is alsogiven a mechanical bias to assist in holding itself away from the pole piece. This is accomplished by proper forming of this part at the right angle of the same. The electromagnet (coil and stationary magnetic structure) is sufiiciently strong to surelyatt 'act armature 6 to pole piece 10 which current is passed through the coil, despite the two restoring forces mentioned. V

A silver contact 19' is screwed intosmagnet 18. The latter supports the pair by welded or soldered attachment to header pin 4.

In a similar manner, normally open silvercontact is supported by another header pin 21.1 The air gap betweenthis contact and the mating one 14 on the armature is larger than the gap between pole piece 10 and arma:

ture 6 because of the cantilever relation between the two. Particularlyif the armature is lengthened, this may be made of the order of fifteen or more thousandths of an inch and thus qualify my relay to break heavier currents than heretofore possible in such a small relay.

give a wiping action between contacts 14 and 19'.

Excluding the headerpins and the base it is seen that any relay. is constructed of butfive parts; the stationary magnetic member, the coil, the armature, the magnetic normally closed contact and the simple normally open. contact. An equivalent relay of conventional form would have perhaps fifteen pants.

owever, in this case particular importance attaches to this because the common con' 11 with opposite direction of turns as shown for the particular reason that the magnetic material base 1 makes it possible to substantially eliminate an inductive kick in one relay circuit because of energization of an adjacent relay. Without this capability false or partialoperation of one relay upon 'the'actuation of one of its neighbors V V is not induced in one coil circuit by actuation of an ad- There is a demand in the art for multiple relays when these can be made small in size. A common housing for such a group is'often known as a crystal case. because of prior art usage of such a case for mounting a single piezo electric crystal. l have found it possible to fit four of my individual relays insuch a case (as per FIGS. 1

and 2).whereasthe art has previously only been able to fitin twor I fl Thedual structure shown in FIG. 2 is illustrative of my arrangement ofany plurality of individual units commonly mounted. In this figure the second relay is identiarmature placed-on the opposite side of the stationary.

Structure as has been illustrated. 1 place fcoils 11 and relative flexibility .of my thm armature causes mertla to jacentrelay. V V V Rather than to employthe known Armco iron station,- ary magnetic member, whichis a suitable material for the embodiments ofFIGS. 1. and 2, 1 have also found that a ferrite may be used for this member. possible even further structural simplifications. Suchembodiments are shown in FIGS. 3 and 4. 'Inthese, station.-

ary magnetic member 25 is formed in onepicce. This is easily accomplished by the known method of compressing the ferrite powder in a suitably shaped die and: then f sintering the resulting cake in an oven to give the, known ferrite magnetic composition and suitable mechanical strength. j I

Ferrites are known which have excellent insulating properties; from a hundred-thousand to one million ohms per centimeter cube. v These are the nickel-zinc type with possible small amounts of manganese, cobalt-or copper as representative of the former resistivity, and c the nickel alone type for the latter mentioned resistivity. Accordingly, I employ piece 25 asan insulating frame as well as for the stationary part of the magnetic circuit and mount all the electrical circuits on it. Piece 25 has one extremity 26, an opposite extremity 27 (giving a U shape) and a central projection or pole 28. A coil 29, of the same general'characteristics as coil 11 of the prior'embodiment, is wound on a suitable form or in a selisupporting encapsulated form and is slipped down 'over the central pole 28. The latter is of elongat ed form I in orderthat the quadruple form of the relay shownin FIG. 4, specifically, may be accommodated. 'Wnilethe embodiment of FIG. 3 may be taken as the elevation view of FIG; 4 it also illustrates any embodiment from a single i armature oneto any desired multiple of independent armatures. The coil 29 is fabricated .of appropriate width as noted in FIG. 4'to accommodate the multiplicity desired.

' Extremity 26 of the ferrite core is provided with one metallized area 30 for each armature to be employed.

This may be a silver electroplating and the corresponding,

Other sputtering 3 A similar n etallized. area is also included at 32 on opposite extremity 27 of thecferrite, and thisse'rves as a normally opencontact. .Allexible connecting lead 33 is shown connected thereto for an external connection. A

riveted silver contact 34 is'provided in the free end of armature 31, as before, although this armature may he heavily silverplated on 'both sides to give an equivalent contact.

' A U-shaped support 35'is provided tohold the normally closed contact 36 and permanent magnet 37,. Support 35 maybe a stout piece of metal wire that is prcssed or ,molded into ferrite 25 near extremity 27. Since the fer- V rite isa good insulator an electrical short will not be established to the other'contact 32. In this embodiment permanent. magnet 37 is of rectangularform, having. a a

north magnetic pole atone end and a south magnetic'pole at the other asindicatedby the N and S in FIG. 3.

Silver contact 36 may be welded or threaded into magnet 37 and the magnet spot welded 'to support 35. Flexible lead .38 connects tocontact 36 for external connection thereof and flexible lead 39 to armature 31 to make the common connection of the relay thereto.

The cantilever action of armature 31 previously described will be seen to apply to the embodiment of FIG. 3, and even to a greater degree than before. Of course, the proportions of either embodiment may be "altered to give any degree of such eifects as will be apparent from a study of the figures.

In FIG. .4 the same general structure described in connection with FIG. 3 is to be found, but repeated four times over. Thus, identifying numerals have been given one,

two or three prime marks for corresponding elements. It will be seen that this embodiment differs from that of FIG. 2 in that in FIG. 4 all the armatures 31,31, 31"

and"31 are actuated at once upon energization of coil 29, while in FIG. 2 separate coils 11, 11', etc. may provide separateenergization.

In any of my embodiments Ihave found the'contacting function substantially free of bounce by means of oscilloscopic measurements. a This is because of the wiping action of the contacts, as has been described.

In FIG. 4 all of thecontacts may be paralleled by carrying the areas 30 and 32 all across the respective extremity faces 26 and 27. In this way increased reliability of operation and increased current carrying capacity may be achieved. As shown in FIG. 4, with the separate contacts along each extremity, each contact can be connected to a separate circuit, although the actuation of all the armatures is common because of the one coil 29. This circuit is a four pole double throw switch. With common contacts the circuit is a single pole double throw switch.

In representative embodiments the power required for actuation is of the order of milliwatts. Of course, for

large embodiments switching many amperes'the actuation effects due to external vibration. The light weight ofthe armature is also afavorable factor in this performance.

Various other modifications may be made'in the arrangement, size, proportions and shapes of the illustrative embodiments shownand in certain substitutions of elements from one embodiment to another-without. departing from the scope of my invention.

1 Having thus fu ly described my invention and the manner inwhich it is to be practiced, I claim:

1. In a relay structure having one, magnetic member of an insulativeferrite material and means to magnetize said member forthe actuationof said relay, plural armatures of magnetic spring material each rigidly fastened to one extremity of said member to extend to the opposite extremity of said member as a cantilever for attraction to said member upon energization of said means to magnetize, a magnet of fixed magnetomotive force adjacent the free end of each said armature to attract the free end of each said armature away from said opposite extremity save when said means to magnetize is excited, a first contact upon each said magnet, a second contact mating there with upon the free end of each said armature and a third contact mating with said second contact oppositely to said first contact, the spring of each said armature causing a wiping action at each pair of mating contacts.

2. In a relay structure having a stationary magnetic member and means to magnetize said member for the actuation of said relay, at least one armature of spring magnetically attractive material stiffly attached to one extremity of said member to overhang the opposite extremity of said member as a cantilever for flexural attraction to said member upon energization of said means to of said armature positioned to hold said free end of said armature away from said opposite extremity save when said means to magnetize is excited, a first electrical contact upon said magnet, asecond electrical contact mating therewith upon the free end of said armature and a third electrical contact mating with said second contact oppositely to said first contact, each pair of mating contacts being given "a wipe action upon coming together by the flexural characteristic of said armature in combination with'the geometry of said stationary magnetic member and said armature as a magnetic circuit.

3. A relay structure comprising at least one magnetic path, at least one spring armature, said armature attached to one extremity of said magnetic path and extending over the other extremity of said path for magnetic attracof said armature, said second contact spaced to contact said armature contact when said magnetic path is not energized, and magnetic means adjacent said second contact to attract said armature to said second contact when said magnetic path is not energized.

4..A relay structure comprising at least one stationary magnetic path, at least one leaf spring armature, said armature rigidly attached to one extremity of said'stationary magnetic path and extending over and beyond the other extremity of said path for magnetic attraction thereto, only onecoil of wire surrounding each said stationary path intermediate the two extremities thereof, a'n armature electrical contact directly upon the free end of said armature, a normally open stationary electrical contact aligned with said armature contact on the side of said armature toward said stationary magnetic path, a normally'closed stationary electrical contact aligned with said armature contact on the side away from said stationary magnetic path, said normally open contact spaced to contact said armature contact when said coil is energized with electric current and to impart a sliding motion to said armature contact by virtue of the spring characteristic of :said armature as the magnetic attraction of said stationary magnetic path. is continued upon said armature, said normally closed contact spaced'to contact said armature contact when said coil is not so energized, and a permanent magnet adjacent said normally closed contact to attract said armature to said closed contact when said coil is not so energized.

5. A multiple electric relay structure comprising plural individual similar magnetically operated relays each having a coil and a magnetic circuit, a base of magnetic material common to all said relays, each magnetic circuit of adjacently mounted said relays oppositely mounted in magnetic proximity to and on one side of said base, each coil of adjacently mounted said relays having turns wound in opposite directions in relation to said base, said coils having a common electrical circuit; the recited magnetic configuration effective to inhibit spurious actuation of a relay upon the actuation of an adjacent relay because of the recited relation between the coil circuits and the magnetic circuits of said multiple electric relay structure.

6. An electrical relay comprising a magnetic core of ferrite, a coil upon said core, electrically conductive areas formed upon extremities of said core, a conductive spring armature attached to one said area upon one of said extremities, said armature formed for magnetic attraction to said core upon the electrical energization of said coil and to pass adjacent to the opposite of said extremities,

frame in addition toa magnetic core.

a contact upon said armature at said opposite extremityto ;mate with said conductive area thereon, means to sup- ,portattached tosaid opposite extremity, amagnetattached to said means to support adjacent to said armature and across said armature from said conductive area upon said opposite extremity, another contact mounted upon said means to support to mate with said armature contact; said magnet coactive with said armature to retain said armature in contact with said other contact save when said coil is energized; in the recited structure said ferrite acting as an insulating frame in addition to-a magnetic core. a v 7 7. An electrical relay comprising I an E-shaped mag netic coreof a nickel ferrite, a coil on the middle arm of said 'E, one electrically conductive area plated upon each of the outer arms of said- E, a spring steelarmature rigidly and conductively attached to one said area upon one said outer arm, said armature formed to pass adjacent, to thermiddle arm of said E for magnetic attracmanent magnet and, a mechanical bias upon saidyarmaturecoactive to retain said armature in contact with said normally closed contact save when said coil is energized; in the recited structure said ferrite acting as an insulating 8.- An elect 'cal relaycomprising a high resistivity'ferrite magnetic core'having two'ends, magnetomotive-producing means upon said core, plural separate metallized areasformed upon each said two ends aligned oppositely one to the other, plural separate conductive spring armatures each'attached to one of said 'pluralseparatemetallized areas upon one said end, each said armature formed topass over an, aligned separate metallized area upon said other end, a contact upon each said armature to mate with said aligned separate metallized area, a magnet adjacent to each said armature and opposite to the mating said aligned separate metallized area, another contact adjacent to each'said magnet and adjacentsaid contact upon each said armature to mate therewith, means to supp rt said magnets and said other contacts from said core, ,each said magnet coactive with said armature ad- .jajcent ,to it to retain said armature ag-ainstsaid'imagnet save-when said magnetomotive-producing means is energized; said ferrite forming an insulating frame for the electrical conductors attached'thereto.

V 9, "Ihe electrical relay of claim 8 in which the metallized area upon eachof said ends of themagnetic core are common to the said pluralseparate armatures -to provide multiple operating elements to a single pole contactofsaidrelay 8 -V :1 a

'10. A multiple electrical relay comprising an E shaped magnetic core of a zinc-nickel ferrite, an oval cross-section coil upon the center arm of said E, plural separate electrically conductive areas formed uponleach outer arm of said E along the major axis of said oval coil and aligned oppositely. on one said outer arm with respect to the other, plural,separate armatures of spring conductor firmly attached to said corresponding plural separate conductive areas of one said outer arm, each said armature rectilinearly formed to pass over said center armof said 1 E .and also vover an aligned separate conductive area upon said opposite outer arm, a contact upon each said armature to mate with said aligned separate conductive area,

plural vmeans to support attached to said opposite outer arm, a permanent bar magnet attached to each said means to supportadjacent to each said armature and and means to actuate the same, a base of magnetic ma- .terial common to all said relays, the magnetic circuit of each adjacently mounted relay oppositely mounted in magnetic proximity to said base, said-means to actuate of adjacently mounted said relaysconstituted to produce magnetomotive 'forces in opposite directions in relation to Said base, the recited magnetic configuration effective to inhibit spurious. actuation of a relay upon the actuation of an adjacent relay, and a mechanical configuration in which the various elements are mounted exclusive- 1y on header-pins embedded in'an insulator having the electrical and physical propertiesof glass, said insulator disposed in holesin said common base. I 1

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